Recuperative counter-flow furnace



Aug. 29, 1933. E. L. SMALLEY RECUPERATIVE COUNTER FLOW FURNACE t INVENTOR.

2 Sheets-Sheet l Original Filed June 5, 1929 w dwl H ww m Y a A E 5 @Y Q,

Aug. 29, 1933. E. L. SMALLEY 1,924,167

RECUPERATIVE COUNTER FLOW FURNACE Original Filed June 5, 1929 2 Sheets-Sheet 2 INVENTOR. fulw/i w Q BY 9 g :5 E w A TTORNEY Patented Aug. 29, 1933 UNITED REcUPEnA'rIvr: coU TER-Fmwjeemnce Edwin LQSmalley, Whitefish- Bay, Wis., assignor' :to Hevi' Duty Electric Company, Milwaukee,

Wis., a Corporation of Wisconsin Original application June 5,19 9, serial f sh. 368,646. Divided and this application 'July 10,

1930. S erialNo.467, 077 1 My invention relates broadly to furnacesand tive counter-flow type. a

, This application is a division, of myapplica tion Serial No. 368,646, filed June 5,. 1929, for recuperative counter-flow furnace.

One of the objects of my invention 'is to provide a construction of recuperative counter-flow furnace in which minimum floor area is'necessary for the installation of; the furnace for th heat treatment of materials.

Another object of my invention-is to pro-- vide a furnace structure in whichthe tempera- 'ture of the articles or material to be heat treated may beuniformly raised, by a preheating process, the articleor material thensubjectedto a uniform heat treatmenttemperittUre: and

thereafter the articles or material reduced in temperature at a uniform rate,

Still another object of my inventionis to provide a construction of heat. treatment furnace with parts arranged to control the directionof convection heat currents for the preheating,

heat treatment and temperature reducing processes to which the material 01' articles being passed through the furnace may be subjectedf A further object of my invention is to provide a construction of recuperative counter-flow furnacein which means are provided for moving articles through the furnace, with automatic means at one end of the furnace for imparting moving-forces to the moving system by which the articles are carried,and means iatt'ne other end of the furnace for removing articles therefrom-to allow the entry of articles to be'sub jected to heat treatment.

A still further object of my invention is to provide a construction of recuperativecounter- -flow furnace having means for shifting material subjected to heat treatment 'from one chamberto another for the horizontal movement of the material through the chambers during the course of preheating, heat treatment and cooling processes. i v

Another object of my invention isito provide currents which circulate through the; cooling chambers, in (directions where the convection currents may be controlled to-effect maximum coolingwhile maintaining temperature uniform- 1 meansareprovided.for fdistributing the cooling I ,more particularly to a furnace of the recupera-- ity of the successive parts of the charges as they 7 movethrough the cooling chambers. I a

g A further object of. my invention is to ;pro vide a mechanical system for loading a preheating chamber ofthe recuperative counter flow furnace at one end while removing a charge in timed relation theretoat the opposite end "of the furnace i .Other and further objects of my invention reside in thGmCOIlStIllClilOIl .of g a recuperative counter-flow -furnace, as will be? more fully pointed out inthespecificationhereinafter fol- Y lowing by reference to the accompanying draw ings, in'which: V

. Figure 1 'is a longitudinal cross-sectional view taken centrallythrough a combined preheating,

heat treatment and a cooling chamber arrangehaving construction-embodying the principles of my invention; Fig. 2 is across-sectional'view through the cooling and? preheating chamber 2-2 ofFig. l;- Fig.' 3 is a cross-sectional view taken on line 3'3-of Fig. 1 showing the arrangement of the;heat';treatment chambers in the horizontal typeof-recuperative counter-flow furnace; Fig. l is alongitudinalcross-sectional 1 view taken through; the horizontal type of re cuperative c'ounter-flow'furnace onv line H of Fig. 2; Fig. 5 is a.,.plan view of the floor plate in thelcooling andrpreheatingchambers of the recuperative counter-flow furnace construction illustratedin Figs. 1 4; and Fig. 6 isa diagrammatic .view explaining onexmanner of. moving chargesthroughthefurnace.

pReferring. toithe drawings in detail the furnace system ,of my invention comprises a multiplicity of chambers disposed a(fiac.ent each other, one of :the chambers comprisinga preheating chamber,,the:next succeeding pair ,of chambers having heat'treatmentmeans therein,

'ment' inarecuperative counter-flow furnace construction of thefurnace illustrated on line and the. final chamber comprisinga cooling chamber. 3 v

Referring to.the drawings, the furnace system of myinvention has been illustrated where"- in the preheating, heat treatment and cooling chambers are, located in horizontal alignment" adjacenteach other as shown in Figs. 1-4; *The V heat treatment chambers are shown sideby side at .47 and 48,. one Ipreheatin'g chamber: 49a being although any method of heating may be em-" ployed. The walls of the furnace 51 are of suitable fire brick and heat insulating material and .a furnace shell is provided enclosing the furnace walls. Pushing mechanisms may be used for progressing the charges through-the furnacev on trays 19. The cooling chambers are connected with adjacent preheatingchambers by flues 54 which. receive convection currents'through; ports 52 of the cooling chambers and 50a and conduct such convection currents through ports 53 in the arches of preheating chambers- 49 and'49a, where the-charges on trays .19 in preheating chambers are preheated. Trays 19 j preferably have a perforated bottom through which convection gases as indicated by arrows in Fig. 2 may readily pass. This is especially desirable-when the tray supports a charge through which convection gases may readily now. The convection of air currents. is downward through the ports 55 of ceramic or'metallie-refractory plates 56 forming the 'supportfor rails 17 then along horizontal flues 57 and upwardly through the ports or openings 55 in plates 56 in the cooling chambers '50- and 50a. The

' ports 55 in the plate 56-, as shown more clearly in Fig. 5, are graduated, with the largest cpenings farthest from the 'cooling charge, to control the direction of flow of the airor gases. The convection currents, shown by arrows in. Fig. 2, are guided by ports '52, flue 54, ports 53, ports 55 and flue 57, in such manner as to'fully distribute the cooling-influence of the air on the charges in the cooling chambers 50 and 50a WhatI claimas newand while preheating the charges introduced in pre,

heating chambers '49 and 49a. The paths of movements in reverse direction of the two charges passing through the furnace have been shown-by arrows 59 and 59a, where each charge is gradually progressed through a preheating chamber to the heat treatment chamber, and then through a'cooling chamber.

In Fig. 6 I have shown a method of loading the 'furnacewhere a suitable formof reciprocatory pusher apparatus is indicated at 60 for shifting a'loaded tray 19 into the preheating chamber. As the tray passes from cooling chamber it is disposed upon a suitable platform or conveyor .61 and may be removed therefrom, byany suit able means. It will be understood thata sim ilar reciprocatory pusher mechanism maybe employed in directing loaded trays: in their course of movement in the opposite direction through the adjacent duplex chamber system'in the furnace structure of myin'vention;

While'I have described my invention in one of itspreferred embodiments I desire that it be understood that modifications may be made and that'no limitationsupon my invention are intended other than are imposedby the scope of the appended claims.

desire to secure by Letters Patent of the United States is as follows:

1. In a furnace, a plurality of chambers comprising preheating, heating and cooling chambers disposed in horizontal rows adjacent each other, the chambers in each row being aligned end to end for the passage of material to be heat treated therethrough, the preheating chamber of one row being directly adjacent the cooling chamber of another row, the heating. chamber of one row being directly adjacent the heating chamber of another row and the cooling cham- 1 ber of the first mentioned row being immediately adjacent the preheating'chamber of the second mentioned row, bottom plates closing each of saidpreheating and cooling chambers'and apertured for the uniform distribution of convection currents therebetween, the upper portion or said preheating and'cooling chambers being connected by flues one with the other, and vfiues interconnecting said chambers below said bottom plates for uniformly directing the circulationof conve'ction currents through said cham bers and through the fiues interconnecting said chambers. e

' 2. In "a furnace, a multiplicity of chambers comprising preheating, heating chambers aligned in horizontalrows disposed porting bottoms'for each of said preheating and cooling chambers, each of said .plate members being provided with apertures varying insize from a relatively small cross-section adjacent;

division wall to larger cross-sections remote from said division wall, for the distribution of convection currents therethrou ghgthe upper portions of said preheating and cooling chambers beingapertured for providing a path for the i circulation of convection currents, and fines in the upper and lower portions of said preheating and cooling chambers for directing convection currents therebetween through the apertured upper portions'and said apertured bottom plate and cooling one adjacent the other with a division wall therebetween, plate members-formingthe supmembers of the preheating and cooling cha nbers. I Q

3. In a furnace, a refractory housing, a division wall extending longitudinally thereof, a

multiplicity of chambers aligned end to end in a horizontal plane on each side of said division wall comprising preheating, heating and cool- 1 ing chambers, bottom plates extending across said'preheating and cooling chambers, said plates being apertured for the passage of convection currents therethrougn, the upper portions of said preheating and cooling chambers being apertured for the circulation of convection currents, flues interconnecting the lower portions of said preheating and cooling chambers beneath said apertur d plates, flues connecting the upper portions of said preheating and cooling chambers above the apertures therein, the apertures in said plates and. the apertures in the upper portion of each of said last mentioned chambers graduating in size from a minimum adjacent the wall dividing said last mentioned chambers to a maximum adjacent the walls of the refractory housing for distributing the convection currents through preheating and cooling chambers uniformly throughout the area thereof;

4. In a furnace; a pairof rows of longitudinally aligned chambers, a wall, dividing said chambers into cooperatively related adjacent sections, the intermediate sections constituting heat treatment chambers, the sections on one end thereof constituting preheating chambers and cooling chambers respectively, and the sections on the opposite ends thereofconstituting cooling and preheating chambers respectively,

lateral fiues interconnecting one of said cooling chambers with the adjacent one of saidpreheating chambers, and ports between said fiues and said preheating and cooling chambers, said.

ports varying in cross-section froma minimum size adjacent the wall intermediate said precontrolling the'temperature conditions therein.

5. In a furnace, amultiplicity of rows of longitudinally aligned chambers disposed side by side, a walldividing said chambers into a plurality of adjacent sections, the intermediate section in each row constituting a heat treatment chamber and the sections on either end thereof constituting preheating and coolingv chambers respectively, the order of chambers in one row being reversed with respect to the order of 'the chambers in the adjacent row, fiues interconnecting the preheating and cooling chambers atone end of said rows and separate fiues interconnectingthe cooling andpreheating chambers at the opposite end of said rows, and ports disposed be: tween said fines and said preheating and cooling chambers, said ports increasing in cross-section from a minimum adjacent the wall dividing said preheating and cooling chambers to a maximum adjacent the outer wallsof said'chambers for graduating the temperature conditions therein.

6. Ida furnace, a duplex system of chambers,

a wall dividing said system of chambers into a, plurality of sections disposed end to end, the

intermediate section .of each system comprising a heattreatment chamber and the sections on each end thereof constituting cooling and preheating chambers respectively', supporting plates extending across the bottom of each of said cooling and preheating chambers, ports in said plates, and fines beneath said plates interconnecting adjacent cooling and preheatingchamhere, said ports increasing in cross-section from a minimumadjacent thewall between said preheating and cooling chambers to a maximum adjacent the outer walls of said chambers.

7. In a furnace, a duplex system of chambers, a wall dividing saidsystem of chambers into a plurality of sections disposed end to end, the intermediate sections, constituting heat treatment chambers and the sections on opposite ends thereof constituting preheating and cooling chambers respectively, the preheating and cooling chambers in said duplex system of chambers being disposed laterally side by side, 'fiues interconnecting the upper and lower portions of said preheating and cooling chambers, ports disposed between the ends of said fiues andsaid preheating and cooling chambers, said ports varying in cross-section from a minimum size adjacent the mediate sections constituting heat treatment chambers andthe end sections constituting preheating and cooling chambers respectively, with,

the preheating chamber in one row directly ad- I jacent the cooling-chamber of the'adjacent row,

fiues interconnecting the top of the preheating chamberv in one row with the top of the cooling chamber in the adjacent row, supporting plates extendingacross the bottom of said preheating and cooling chambers and ports in said plates, said ports increasing in cross-section from a minimum adjacent the division wall between said preheating and cooling chambers to a maximum adjacent the outer walls of said chambers for the circulation of convection currents between said preheating and cooling chambers during the course of movement of articles under heattreatment through said chambers in opposite directions. i

9. In a recuperative counterfiow furnace; a multiplicity of aligned chambers disposedlongitudinally end to end and laterally sideby side,

a longitudinally extending wall dividing said chambers into a multiplicity of sections, the intermediate sections constituting heat treatment chambers and the adjacent end sections constituting preheating and cooling chambers respectively, transverse flues interconnecting the top of adjacent preheating and cooling chambers at one end of said furnace, independent sets of transverse flues interconnecting the top of the cooling andpreheating chambers at the opposite end of said furnace,-supporting plates extending across the bottom of said preheating and cooling chambers, flues beneath s'aid plates interconnecting the adjacent preheating and cooling chambers and ports in the tops of said preheat- .ing and cooling chambers and in saidplates, said ports being graduated in size from a -minimum r adjacent the wall between saidpreheating and cooling chambers to a maximum adjacent the remote walls of said chambers for'the' distribution of convection currents through the preheat- "eachother, the chambers injonerow compris ing a preheating chamber, a heat treatment chamber and a cooling chamber arranged'in the order named and the chambers in the adjacent row'comprising a cooling chamber, a'heat treatment chamber and a preheatingchamber arranged in the, order named, laterally disposed fiues interconnecting said cooling andpreheating chambers, and a plurality of ports disposed between the ends of ,said fiues and said preheatingand cooling chambers, said ports grad uating in size from a relatively narrow width adjacent said preheating and cooling chambers to a greater widthremote from said preheating and cooling chambers.

r EDWIN LJSMALLEY; 

